Safety hatch operating mechanism



R. KERR SAFETY HATCH OPERATING MECHANISM Sept. 6, 1949.

Filed April 18, 1947 (Ittornegs Patented Sept. 6, 1949 UNITED STATES PATENT-OFFICE SAFETY HATCH OPERATING MECHANISM Robert Kerr, Detroit, Mich.

Application April 18, 1947, Serial No. 742,263 3 Claims. (01. 292-21) This invention relates to emergency escape exits, and in particular to safety hatches in vehicle roofsand operating mechanism therefor.

. One object of this invention is to provide an operating mechanism for a vehicle roof safety hatch which operates automatically to unlatch the hatch inthe event that the vehicle turns over on its side, thereby enabling the passengers to escape through the opening thus provided without the danger of their being trapped ,inside the vehicle.

Another object is to provide an operating mechanism for a vehicle roof safety hatch wherein the hatch is provided with oppositely movable latches which, in turn, are connected to a slidable weight by way of a rotary cam whereby the overturning of the vehicleonto its side will shift the sliding weight by means of gravity rotating the cam and unlatch the vehicle hatch.

Another object is to provide an operating mechanism for a vehicle roof safety hatch, as set forth in the preceding objects, wherein the latches engage keepers with a camming or wedging action such that the safety hatch is held FigureZ is a longitudinal'vertical section along the line 2-2 in Figure 1;

Figure 3 is a transverse vertical section along line 3 3 in Figure 1;

Figure 4 is a top-plan view of an end portion of a vehicle showing diagrammatically a roof safety hatch according to the present invention,

with a portion of the hatch broken away to reveal the hatch opening; and

Figure 5 is a side elevation of the portion of the vehicle shown in Figure 4.

Referring to the drawings in detail, Figures 4 and 5 show a vehicle, such as a motor bus, generally designated Ill, having a safety hatch generally designated ll mounted in an opening I2 in the roof l3 of the vehicle H], the safety hatch ll being operated by operating mechanism generally designated !4, according to a preferred form of the present invention. The vehicle In is provided with the usual door I5 and windows Hi.

The opening 12 in the roof l3 (Figures 2 and 3) is surrounded by a coaming ll topped by a resilient gasket 18 of rubber or the like. The

2 hatch II has a plate-like central portion l9 and a downwardly-extending rim portion 29 which overlaps the coaming I! and provides a seal against the entrance of moisture in cooperation with the gasket l8.

The hatch l I is releasably secured to the roof l3 by means of mechanism engaging a pair of keepers 2| which are secured as at 22 to the in side of the roof I3 immediately beneath the coaming H. The keepers 2| are provided with sockets or recesses 23 having inclined wedging surfaces 24 (Figure 2) Cooperating with the recesses 23 are slidablerlatch bolts 24 having inclined wedging ends '25 engagin the inclined wedging surfaces 24 of the recesses 23 in the keepers 2|. Accordingly,-when the latch bolts 24 are pushed outward toward the keepers 21, the opposing wedging surfaces 24 and 25 cause the hatch l l to be drawn downward more tightly against the gaskets I8.

The latch bolts 24 are guided in their reciprocation by spaced inner and outer guide brackets 26 and 21 having guide slots 28 and 29 respectively. The outer guide brackets 21 are bolted directly to the underside of the hatch I I, whereas the inner guide brackets 26 are bolted to a pivot platezll which, in turn, is bolted, welded or otherwise secured to the underside of the hatch II.

Projecting from the central portion of the pivot plate 30 is a pivot stud 3| passing through a hole 32 in the center of a cam disc 33, the latter being held in place by a retaining nut 34, threaded upon the outer end of the stud 3!. The cam disc 33 is provided with a pair of cam grooves or slots 35, each consisting of a pair of partially spiral arcuate portions 36, which, at their meeting points 31, are farther from the pivot stud .3! than at their opposite ends 38. The cam grooves or slots 35 are engaged by pins 39 mounted on the inner ends of the latch bolts 24 (Figure 2) and serving as cam followers. In practice, the pins 39 are equipped with rollers to reduce the friction, but for purposes of simplification, these rollers have been omitted and the pins 39 shown as directly engaging the cam groove or slots 36.

Extending radially outward from the cam disc 33 and integral therewith is an operating arm 40 having an elongated longitudinal slot 4|. Engaging the slot 4| is a pin 42 threaded at its lower end (Figure 3) into a hole 43 drilled in the center portion of a sliding weight block 44. The weightsblock 44 is arranged to reciprocate in a direction crosswise of the vehicle and for this purpose is mounted in elongated guiding 3 members 45 bolted to the inner side of the hatch and having retaining flanges 46.

In the operation of the invention, let it be assumed that the hatch H is securely latched by the operating mechanism l4, and that the parts thereof are in the positions shown in Figures 1 to 4 inclusive. In this position, the pins or cam followers 39 are at their farthest positions from the pivot stud 3|. I

If, now, the vehicle It meets with an accident and accidentally turns over on its side, the hatch II will move into a vertical position along with the roof I3. When this occurs, the weight block 44 will slide downward in the now vertical guide members 45, carrying with it the pin 42' and swinging the arm 40. This action rotates the cam disc 33, causing the pins or cam followers 39 to be pulled inward toward the pivot stud 3| by reason of their engagement with the cam groove or slots 35, the inner ends 38 of which are nearer the pivot stud 3| than the meeting ends 31 of the separate portions 36 (Figure 1). As the pins 39 are pulled inward in this manner toward the pivot stud 3|, they cause the latch bolts 24 to slide inward toward the stud 3 I, guided .by the slots.28 and 29 in the guide brackets 26 and 21, and withdrawing the ends .25 of the latch bolts 24 from the recesses 23 in the keepers 2|.

When the latch bolts 24 have thus been withdrawn from latching engagement with recesses 23, the hatch H, thus freed from its locking connection with the vehicle roof l3, falls outward by its own weight and clears the opening 2 so that the passengers in the vehicle ma escape. Thus, in case of the door 15 or'windows It being jammed or inaccessible as a result of an accident in which a bus turns over on its side, the passengers will still be provided with an escape opening which is easily accessible, and which requires no climbing on the part of the passengers, some of whom may beinjured and unable to climb. The safety hatch of this invention thus works automatically to free the otherwise trapped passengers, and enable them to escape quickly from the overturned bus, a matter of supreme importance if a bus catches fire. The hatch is, therefore, a valuable device for saving. lives after vehicle accidents have occurred.

WhatIclaim is:

1. An automatically-released latching device for a vehicle roof safety hatch comprising a latch keeper having a latch bolt receiving portion secured to the vehicle roof, a latch bolt slidably mounted on said hatch and having a cam follower connected thereto, a cam rotatably mounted on said hatch and having an arcuate cam shoulder thereon arranged at a varying distance from the axis of rotation thereof and engageable with said cam follower, an arm secured to said cam, and a movable Weight operatively connected to said arm to shift said arm and rotate said cam in response to the motion of said hatch into a vertical position, said cam shoulder having two portions extending spirally inward in opposite directions from a common junction.

2. An automatically-released latching device for a vehicle roof safety hatch comprising two latch keepers mounted on opposite sides of the hatch opening, each keeper having a latch bolt receiving portion therein, two latchbolts slidably mounted on said hatch in alignment with said keepers and slidable simultaneously in op posite directions into and out of engagement therewith, a cam disc rotatably mounted on said hatch and having a pair of arcuate cam recesses therein arranged at varying distances from the axis of rotation thereof, said latch bolts having cam followers projecting therefrom into said cam recesses, an arm secured to said cam, anda movable weight operatively connected to saidarm to shift said arm and rotate said cam in response to the motion of said hatch into a vertical posi tion, each of said cam recesses having two branches extending spirally inward' in opposite directions'from a common junction.

3. An automatically-released latching device for a vehicle roof safety hatch comprising two latch keepers mounted on opposite sides of the hatch opening, each keeper having a latch bolt receiving portion therein, two latch bolts slidably mounted on said hatch inalignment with said keepers and slidable simultaneously in opposite directions into and out of engagement therewith, a cam disc rotatably mounted onsaid hatch and having a pair of arcuate cam recesses therein arranged at varying distances, from the,

REFERENCES CITED The following references are of recordln the file of this paibent:

UNITED STATES PATENTS Number Name Date 248,086 Cassidy Oct. 11, 1881 950,551 Ledoux et al. .Mar. 1, 1910 1,567,662 Mack Dec. 29, 1925 2,389,315 'Kerr Nov. 20, 1945 

